I am assuming ur are trying to download 12.1.0.2 EM on linux and this can be done from OTN- http://www.oracle.com/technetwork/oem/enterprise-manager/downloads/index.html
What error are you getting when you use unzip ? Also make sure that you use unzip6 version.
I hope you are not trying to extract linux binaries on windows host ?
After downloading binaries from OTN, pls verify the checksum/bytes of the zips as mentioned on the OTN

Can you drop me an email with the error, so that i can reach out to you. I am downloading the linux em bits on my linux machine to verify if OTN site is all ok.
I also saw : why do you have extra .zip in the end of : - em12cr2p1_linux_disk3.zip.zip or em12cr2p1_linux_disk3.zip.ZIP
akanksha.sheoran@oracle.com

I dont think that it is upending with “.ZIP” unzip is just giving probable cause of this error
unzip: cannot find or open em12cr2p1_linux_disk3.zip, em12cr2p1_linux_disk3.zip.zip or em12cr2p1_linux_disk3.zip.ZIP.